Gammon M. Earhart, P.T., Ph.D.

In 2005, Gammon M. Earhart, P.T., Ph.D., was a new faculty member at Washington University School of Medicine in St. Louis, MO, studying differences in movement patterns between people with Parkinson's disease (PD) and healthy people. She was interested in why, when some people with Parkinson's disease turn around, they experience "freezing," the sudden inability to move. Then she learned of a study in which elderly people who were at high risk for falls improved their balance simply by learning how to dance the Argentine Tango.

For Dr. Earhart, it was an "Aha!" moment that opened a new direction for her research. Is it possible, she wondered, that dance lessons may also help improve balance among people with PD, whose risk of falls is high?

"Tango incorporates many of the movements that people with Parkinson's have difficulty with, including turning," explains Dr. Earhart. "The more I thought about it, the more it made sense. For example, falls often occur when people with PD try to step backward. If you are dancing Tango as the follower, you are dancing backward and learn a strategy for doing it. Also, there are many ways to turn in Tango, and there's lots of starting and stopping. Learning to execute and manage these movements could be valuable to people with PD."

So, Dr. Earhart began studying the Tango for Parkinson's disease. In 2010, PDF selected her for a research award through its International Research Grants Program, to test the idea for a year. (In 2011, she applied for and received a second year of funding.) International research grants are designed to support researchers who are trying out daring new ideas. The grants enable them to gather the preliminary data they need to make their case for additional funding from major agencies such as the National Institutes of Health.

Dr. Earhart's study included 52 volunteers who were living with Parkinson's disease and who were experiencing common problems with movement and balance. At the beginning of the study, they were performing similar levels of physical activity. About one half of the volunteers were assigned to take Tango lessons for a year, under the supervision of Dr. Earhart and her colleagues; the other half maintained their normal routines. It turned out that many of the Tango students experienced improvement in their Parkinson's disease symptoms. They were also able to walk farther and faster, and their balance improved. Among the non-Tango group, movement symptoms worsened or held steady.

Researchers also found that, over the course of a year, the people with PD who had learned Tango increased their participation in such activity areas as shopping and household tasks; leisure pursuits, including watching movies and gardening; and social activities such as eating out and spending time with friends. In many cases, they were resuming activities that they had put aside when they were diagnosed with PD. In the non-Tango group, no such changes were observed.

As with all forms of exercise, the benefits of Tango diminished when people stopped doing it. But Dr. Earhart thinks that people may find it easier to keep up the Tango than it is to keep up with traditional exercise programs. "People are more likely to continue doing it just because they enjoy it!" she says.

Dr. Earhart, along with her colleague, Ryan P. Duncan, D.P.T., published these findings in two medical journals. Now she is in pursuit of the answer to her next scientific question, namely: can exercise, including dance, slow or stop the changes in the brain that occur in PD? Having gathered initial data with PDF's support, she is investigating this bigger question with support from the NIH in the form of an R01 grant. She is studying brain activity before and after volunteers learn Tango, using functional magnetic resonance imaging (fMRI).

Says Dr. Earhart, "Without our initial Tango study, and funding from PDF, we simply wouldn't have been able to gather the preliminary data necessary to secure funding for a larger project."

Dr. Earhart's research was funded through PDF's International Research Grants Program. In FY2013, PDF is supporting the program with $1.16 million.